Mining machine



' Aug. 29, 1939.

1.. E. MITCHELL MINING MACHINE f/YVE/VTOF. LEWIS EMITCHELL,

LJE MITCHELL MINING MACHINE Aug. 29, 1939.

Original Filed April 25, 1936 7 Sheets-Sheet ATTX Au 29; 1.939. L; E, MITCHELL I I 2,171,162 MINING MACHINE I Original Filed April 25, 1936 7 Sheets-Sheet 3 VE/YTOR: 4 LEWIS E. MITCHELL,

g- 1939- E. MITCHELL 3 MINING lam-nus 7 Sheets-Shee t 4 Original Filed April 25, 1936 E. MITCHELL 2,171,162

- MINING MACHINE Original Filed April 25, 1936 7 Sheets-Sheet 5 E Y PV 7 N E n s W w m w L \fl .w: 0: NE JF m w rmNN mmm NmN w% 0% EN ma 0% L \l m& 5 N: w u w Aug. 29, 1939;

Aug. 29,1939. E. MILI'CHELL MINING MACHINE Original Filed April 25, 1936 7 Sheets-Sheet 7 WEE; NE /T Wm. v N

MI/Q 5Q wt 2 mm. mo.

Patented Aug. 29, 1939 UNITED STATES PATENT OFFICE MINING MACHINE;

poration of Ohio Original application April 25, 1936, Serial No.

Divided and this application March 17, 1937, Serial No. 131,376. Renewed May 27,

21 Claims.

This invention relates to a mining machine and more particularly to a mining machinei adapted to cut horizontal kerfs in a coal mine.

An object of the invention is to provide a mining machine of the above mentioned type having a frame with a flat bottom adapted to rest directly on a mine floor and to slide thereover, which machine is provided with a very compact means to slide it over the mine floor.

Another object of the invention is to provide an extremely compact mining machine of the type above mentioned yet to provide a machine which is extremely flexible.

A further object of the invention is the provision of improved planetary gear mechanism for driving a feeding rope drum on the axis of the shaft connected to the chain kerf-cutter of a mining machine.

A further object of the invention is the provision of improved rope drum feeding apparatus enclosed within the supporting frame but controlled by a single wheel above said frame to effect either haulage speed of the machine or feeding movement thereof.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

The present application is a division of my application Serial No. 76,456, filed April 25, 1936, for an improvement in a Mining machine.

In the accompanying drawings,

Fig. 1 is a plan view of the mining machine comprising my invention with the cutter bar cut off to reduce the length of the drawing;

Fig. 2 is a side elevational view of the device of Fig. 1;

Fig. 3 is an elevational sectional view taken on the line 33 of Fig. 1 looking in the direction of the arrows;

Fig. 4 is a sectional plan view taken on the line 44 of Fig. 3 looking in the direction of the arrows;

Fig. 5 is a sectional elevational view taken on the line 5-5 of Fig. 1 looking in the direction of the arrows;

Fig. 6 is a sectional elevational View taken on the line 66 of Fig. 4 looking in the direction of the arrows;

Fig. '7 is a sectional plan view of a portion of the machine taken on the line l'! of Fig. 6 looking in the direction of the arrows;

Fig. 8 is a sectional elevational view taken on the line 8-8 of Fig. 1 looking in the direction of the arrows;

Fig. 9 is a plan and sectional view of a detail taken on the line 99 of Fig. 3 looking in the direction of the arrows;

Fig. 10 is a sectional plan view of the planetary gear mechanism taken on the line l0lfl of Fig. 3 looking in the direction of the arrows;

Fig. 11 is a plan and sectional view taken on the line lI-Il of Fig. 3 looking in the direction of the arrows;

Fig. 12 is a sectional view of a detail taken on the line l2l2 of Fig. 4 looking in the direction of the arrows; and

Fig. 13 is an end elevational view taken on the line l3l3 of Fig. 12 looking in the direction of the arrows.

The mining machine herein disclosed is generally of the Shortwall type, that is, it is generally employed in a relatively wide room for cutting horizontal kerfs across the face of the mine room. It is particularly constructed for a room and pillar type of mining system employing conveyors in which there will be a face conveyor which runs parallel to the room face and feeds a room conveyor which runs parallel to a rib of the room, said room conveyor feeding entry conveyors of the complete system which will load mine cars.

It is desirable to keep the length of the main frame of the mining machine as short as possible to the end that the face conveyor may be maintained as close to the mine face as possible, whereby supporting timbers or roof props may be provided relatively close to the mine face. It is, of course, evident that both the face conveyor and the mining machine must work between the roof propping timbers and the mine face.

Referring particularly to Figs. 1 and 2 of the drawings it is to be seen that the mining machine comprises a main frame 26 to which is attached for vertical adjustment a kerf cutting mechanism 2|. The main frame 20 is formed of two sections comprising the motor section 22 and the gearing section 23, which sections 22 and 23 are removably attached together as by nuts and bolts 24. By removing the nuts 24, 24, the motor section 22 may be entirely removed from the main frame 20.

The section 23 is welded to and carried upon a flat bottom. or skid pan 25 (Figs. 2 and 6) which is adapted to rest upon and slide over the floor of a mine room. The motor section 22, the bottom of which is flush with the bottom of the pan 25 in direct contact with the mine bottom, comprises a housing within which is mounted an electric motor 26 provided with a rotating armature shaft 21 (Fig. 3) extending into the housing of the gearing section 23 on a horizontal longitudinal axis. To provide access to the brushes of the motor 26, the housing of the motor section 22 is also provided with a pair of flame-proof removable caps 28, 28. (Fig. 1.)

Rigidly attached to and forming a part of the motor section 22 is a control box 29 for the electric motor 26, which is provided with a removable flame-proof cap 39 (Fig. 2) to provide access to the controls therein. A control lever 32 and a reverse lever 31 are provided for controlling appropriate switches within the switch-box 29, for starting the motor 26 and for reversing its direction of rotation. (Fig. 1.)

Adjacent the rear central portion of the motor section 22, is provided a detachable guide sheave 33, Fig. 1, the details of which are illustrated in Fig. and will be described more in detail hereinafter. 7

Also associated with the trailing side of the motor section 22, at that corner thereof remote from the working face of the mine vein, are mounted on the bottom plate 22, Figs. 1, 2 and 5, the guide rollers or pulleys 336 and 331 which may be alternately engaged by a retarding or guide rope or cable 34. The leading side of the motor section 22 as shown in Fig. 1 carries the cable guide rollers 33 and 39, the guide roller 36 being pivoted to a bracket fixed to the control box 29, while the guide roller 39 as shown in Fig. 2 is pivoted to brackets 66, 69 which in turn are pivotally connected as shown at 4 l, 6 i, Fig. 2, to brackets 4|, 6! secured to the motor control box 29. The guide roller 39 may be swung either to its full line position shown in Fig. 1 or to the dotted line position. The electric cable 42 shown in Fig. 1 leads from a distant source of electric power supply to the control box 29, and motor starting resistance 43 may be located in the frame of the motor section 22 in the position illustrated in Fig. 1.

By referring to Fig. 5 is will be seen that the retarding rope drum mechanism 35 comprises a drum 64 journaled on the stationary stub bearing 45 secured rigidly to the vertical plate 46 of the motor section 22. Secured to the vertical plate 46 is a frusto-conical clutch element 47 in position to co-operate with the brake lining 48 carried by the clutch element or brake drum 49 which is rigidly attached to the inner flange of the drum 46. By shifting the drum 62 longitudinally along the stub bearing 65, the retarding force effected by the cone clutch or brake may be effectually adjusted.

In order to shift the drum 4-4 to partially apply the slip clutch shown in Fig. 5, I provide a threaded rod 59 adapted to be received by the thread-ed bore 5! in the axial center of the stub bearing 45, and key a hand wheel 52 to the outer end of the rod 50. The wheel 52 has a hub 53 the inner side of which engages the anti-friction bearing 56 mounted within the cup 54' at the center of the outer flange of the rope drum 44. A collar 55 on the rod 56 is located within the drum 6 as shown in Fig. 5, in position to assure movement of the drum ti l axially of the bearing 45 when the wheel 52 is rotated. The rod 59 is freely rotatable relatively to the rope drum 44 but rotation of the rod 56 by means of the wheel 52 will rotate the inner threaded end in the threaded bore 5| and thereby cause movement of the clutch elements 41, 49 toward or away from each other.

The kerf-cutting mechanism 25 shown in Figs. 1, 2 and 3, comprises a fiat horizontal cutter bar 56 mounted upon and rigidly attached to a cutter bar support or head 57. The kerf-cutting mechanism is adjustable along vertical lines with respect to the main frame 26 and the operating mechanism enclosed thereby.

An endless cutter chain 58 is provided with reversible cutter bits 59 and is adapted to travel around the cutter bar when driven by the sprocket 66 which is mounted upon and keyed to a clutch element 6| as shown in Fig. 3. The sprocket 69 and clutch element 6! are mounted upon a bracket 63 with the ball bearing element 64 intervening. The bracket 63 is shown in Fig. 3, removably attached to the outer bar support frame or head 51 by means of machine screws 65. The clutch element 6| is mounted upon a journal bearing 66 carried upon a stub shaft 61 which is provided with a cap 68 overlying the clutch element and the hub of the spricket 66.

The stub shaft 61 is secured by means of the transverse rivet E0 to the upper end of the hollow or tubular shaft 69 which is splined both internally and externally. By means of the clutch mechanism H, shown in detail in Figs. 3 and 9, the motor 26 may be connected through the vertical tubular shaft 69 to the sprocket 66 to drive the same, as will be hereinafter more fully explained.

As shown in Figs. 2, 3 and 9, the vertical tubular drive shaft 69 is provided with external splines 72 which are engaged by the clutch element F3. The upper side of the clutch element 13 is provided with jaws 14 adapted to cooperate with the jaws 62 on the underside of the clutch element 6!. By means of manually operated mechanism the clutch element 13 can be slid vertically with respect to the splined tubular drive shaft 69, to effect a driving connection between the vertical tubular drive shaft 69 and the clutch element 6! to effect rotation of the driving sprocket 69 of the chain kerf cutter.

Manually operated mechanism for applying or releasing the clutch H is shown particularly in Figs. 3 and 9. A shipper comprising a yoke 75 has a semi-circular groove which fits a circular flange i6 integral with the clutch element 13. It will be evident that free rotary movement is permitted between the flange l6 and the yoke 75. When the chain cutter is being driven, and vertical tubular shaft 69 is being rotated, and since the clutch element 13 is splined to the exterior of the tubular shaft 69, this clutch element will also be rotated and consequently the circular flange '16 will be rotated in the semicircular groove of the yoke '15 when the chain cutter is being driven by rotation of the sprocket 69.

The yoke 15 is provided with trunnions H, N (Fig. 9) journaled in bearings at the outer ends of the lever arms l8, 18 which are pivoted to the transverse shaft i9 which is carried by a pair of bosses 66, 86 screw-threadedly attached to a bottom plate 6| (Fig. 3) of the cutter bar support or head 51.

It should be understood that the operating mechanism for the clutch H must be secured to the cutter bar support frame or head so as to move up and down bodily therewith as the kerfcutting unit is adjusted in elevation relative to the main frame 20, as shown in Fig. 2.

A pair of brackets 62, 82 welded to each other, as shown in Fig. 9, are pivotally mounted on the supporting shaft 19, and are connected to stub shafts 63, 83 by means of the transverse pins 84, 84. The rear ends of the arms I8, 18 are pivoted to the stub shafts 83, 83. Removable cotter pins 85, 85 are provided on the ends of the shaft 19 to maintain the arms 18, 18 in proper relation to the other parts shown in Fig. 9. By removing the cotter pins 85, 85 the arms 18, 18 may be removed to disassemble the entire shipper mechanism for renewal or repairs.

Extending between the U-shaped arms of the brackets 82, 82 and pivotally mounted with respect thereto is a trunnion 86 which is provided with a central transverse aperture adapted to receive an eccentric extension 81 eccentrically mounted upon a cylinder 88 which is rotatably journaled in the bearing 89 carried by the bottom plate 8|, as shown in Fig. 3. A cotter pin 99 is provided to maintain the extension 81 in. the trunnion 86 and to permit removal thereof. The journal bearing 09 is provided with a pair of laterally extending abutments or stops 9|, 9| which are adapted to limit the throw of a handle 92 which is pivotally attached to the cylinder 88 by means of a pin 93.

The handle 92 is provided with a cam 94 adapted to co-operate with a spring-pressed plunger 95 which tends to retain the handle 92 either in the full line position in. Fig. 9 or in the dotted line position. When the handle 92 is in its full line position, as illustrated in Fig. 9, it occupies the position shown in Fig. 3., The eccentric extension 81 will then be in its uppermost position. This will rock the arms 18 about the pivot shaft 19 to move the yoke 15 to its lower position to release the clutch 1|. The handle 92 has a movement through a semi-circular path and the limit stops 9| may be in the nature of clips comprising spaced-apart plates of different lengths with a groove in between for entrance of the lever 92. The pivot 93 may be an eccentric and the spring-pressed plunger 95 may act to hold the arm 92 in either the clip 9| where the clutch II will be applied, or in the other clip- 9I where the clutch will be released. It will thus be seen that the clips 9|, 9| may be used to positively hold the clutch 1| of Fig. 3 either in its applied position or in its released position.

In order to apply or release the clutch 1| of Fig. 3, the handle 92 of Fig. 9 is first swung about the eccentric pivot 93 which assists in moving the lever 92 away from the clip 9|. When the lever 92 is moved from its full line position to its dotted line position as shown in Fig. 9, the eccentric extension 81 of Fig. 3 will be moved to its lowermost position, thus lifting the yoke 15 and thereby causing engagement between the jaws 62 and 14 of the clutch elements BI and 13 of the clutch 1|. This clutch mechanism 1| therefore provides means for effecting a driving connection between the vertical tubular shaft 69 and the cutter chain 58, but it should be particularly noted that by locating the clutch 1| between the upper end of the tubular shaft 69 and the sprocket 69, the motor 26 may be operated to rotate the haulage rope drum while the cutter chain is not being driven.

As shown in Figs. 2 and 3, the cutter bar support or head 51 carries a depending apron having the shape shown in Figs. 2 and 4 and serving as a shield or guard plate for the elevating mechanism hereinafter described, and also as a vertical guard plate overlapping the front end of the main frame, as shown in Fig. 2, in position to abut against the working face of the mine vein when the kerf cutter is being fed transversely of itself along such mine vein. The apron which is secured to the cutter bar support or head 51 and.

depends therefrom, as shown in Figs. 2 and 3, comprises a front downwardly extending plate 96 and a pair of downwardly extending side plates 91, 91 which are rigidly secured by welding to the bottom plate 8|. The front plate .96 preferably tapers toward the rear at each side and is provided with aconnecting crosspiece 91 at its rear end, as shown in Figs. 1, 2 and 3.

The front plate 96 is provided with hooks 98, 98, Fig. 1, on opposite sides of the cutter bar and spaced below the same, as shown in Fig. 2. Also rigidly attached to the bottom plate 8| as well as to the front and side plates 96 and 91, on opposite sides of the cutter bar, are attaching brackets 99, 99 each provided with a pin I90 adapted to be attached to a coupling member IOI of the feed cable I02. As will be more fully described hereinafter, the cable I92 extends from either side of the mining machine to a pulley secured to an anchorage in the mine distant from the mining machine. The feed rope I02 is reeved around such pulley and its free end brought back for connection either to one of the anchorage hooks 98 or to one of the anchorage pins I09. When the kerf cutter is in its lowermost position and the coal being cut is relatively soft, the free end of the feed rope I02 may be connected to either of the anchorages 98. But when the kerf cutter occupies its topmost position or when the coal being cut is relatively hard, it becomes necessary to connect the free end of the feed rope closer to the cutter bar or to either of the attaching brackets 99. The feeding resistance met with by the chain kerf cutter must be balanced against the frictional resistance between the supporting pan 25 and the mine bottom, by so arranging the feed rope I02 in connection with the distant anchorage, and the free end of the rope in proper relation to the mining machine as a whole, with the kerf cutter at adjusted elevation.

As shown in Figs. 2, 3 and 8, the housing for the gearing of section 23 of the mining machine comprises a removable top part attached to a lower part. The lower part is composed of end walls I03, I94 and side walls I95, I95. The walls I93, I94 and I05 are all rigidly attached to the bottom or skid pan 25, as. by welding. The top part of the gearing housing comprises a bottom plate I01, as shown in Fig. 8, welded to end plates I98, I09, as shown in Fig. 3, and also welded to side plates I I9, H9, as shown in Fig. 6. The top part of the gearing section 23 of the mining machine is removably attached to the lower part by means of the bolts I96, I96, as shown in Figs. 2 and 6. The bottom of the lower part of the housing is closed by the skid pan plate 25. In fact, the lower part comprising the bottom plate 5, the end walls I03, I94 and the side walls I95, I95, constitutes the skid pan, removably secured by means of the bolts I96 to the under side of the gear housing 23. The upper part of the housing of the gear section 23 is removably secured to the motor section 22 by means of the bolts 24, 24, as shown in Figs. 1 and 4.

The lower part of the housing of the gear section 23 is also provided with a horizontal reinforcing plate I I8 rigidly secured to the side plates H9 and to the end plate I08. The horizontal plate II8 intermediate the bottom plate I91 and the top plate III, shown. in Fig. 3, is welded to the vertical tube I20 which extends downwardly and is welded at its lower end to the bottom plate I01 to provide ample space for the elevating mechanism connected between the .bottom part of the gear housing and the cutter bar,

Cir

as shown in Fig. 3. The plate I I8 is also welded to the vertical guide cylinders H9 which form par ts of the telescopic guiding mechanism spaced from the elevating device and located between the cutter head and the gear section 23, as shown in Figs. 1 and 8. The plate I I8 is provided with a large circular opening for the feeding rope drum ltd, as shown in Fig. 3; but, nevertheless, the plate IIB extends over a wide area, as shown in Figs. 4 and '7, to provide support for the mechanism by means of which the feeding rope drum is controlled.

As shown in Fig. 8, the cutter head 51 is provided with laterally extending reinforcing plates I25 which are rigidly secured to the plate 8|, which is the bottom plate of the kerf cutting unit, as shown in Figs. 1, 2 and 3.

The kerf cutting elevating mechanism will now be described. Centrally disposed with respect to the cutter head 57 and along a vertical axis which is substantially through the center of gravity of the adjustable kerf cutting unit ZI, I provide a vertical threaded shaft I22 having an upper neck I23 which is rigidly attached to the cutter bar 56 and the cutter head 5?. The vertical shaft I22 is screw-threaded through the upper end of the vertical tubular shaft I2 l mounted for rotation in the cup bearing I25 carried by the bottom plate 25. The upper end of the tubular nut shaft IE3 is journaled in the cup bearing 12s which may be welded to the topplate III shown in Fig. 3.

The upper cup bearing I26 is provided with a lubrication moat I2! having a lubricating opening I23, as shown in Fig. 3. Lubricating material is supplied to the moat E21 by a downwardly extending tube I26 carried by the cutter head 51 and co-operating with the grease fitting I30. Lubricating material supplied by the moat I2'l will lubricate not only the cup bearing I26 but also the upper nut portion I3I of the tubular shaft i2 3, and lubricant may also be expected to seep through the nut I3I and along the screwthreaded shaft I22 and through the bottom thereof to the cup bearing I25.

The lower end E32 of the tubular shaft I24 is jO-LLllELlGd in the cup bearing 25 and provided at its lower end with an annular shoulder to receive the disk plate I34 through an opening in the center of which extends upwardly the hardened bearing pin ltd. The lower end of the pin I33 is provided with a circular head, the underside of which may have the shape of a segment of a sphere so as to. make point contact with the hardened bearing plate I35 resting in a recess in the bottom of the cup I25, as shown in Fig. 3. As before stated, lubricant introduced into the moat EZ'i can by seepage find its way into the cup I25 to lubricate the pin bearing I33 as well as the cup bearing I25.

Keyed to the lower end portion of the tubular shaft I25; is a sprocket ass connected by the endless sprocket chain IS'l to a sprocket I64! to be driven thereby when the clutch M9 is applied. When the sprocket I35 is rotated, the nut I3I at the upper end of the tubular shaft I24 will be rotated, and since the threaded shaft IE2 is held against rotation. by its rigid attachment to the cutter bar 56 and cutter head 5'1, rotation of the nut l3i will result in variation in elevation of the kerf cutting unit. The nut I3I is rotatable in reverse directions and therefore the kerf cutting unit may be elevated or lowered, as desired.

On opposite sides of the cutter head I provide telescopic guiding mechanism which serves not only to guide the kerf cutting unit along vertical lines when adjusted in elevation, but also to cooperate with the spaced-apart vertical hollow shafts t9, I24, and the mechanism connecting the same to the kerf cutting unit, to distribute the feeding strains as the machine is fed by means of the rope feeding mechanism over the mine bottom, particularly when the kerf' cutting unit is at relatively high elevation.

The two telescopic guiding mechanisms are substantially the same construction and therefore common reference characters are used for similar elements. Each of said guiding mechanisms comprises a heavy depending shaft or cylinder I3% which is removably secured by means of a pin I40 to the attaching bracket 99, as shown in Fig. 8. A vertical cylindrical opening through the bracket I39 receives the upper end of the cylinder I38, and the transverse pin Mil extends through the bracket and transversely through the cylinder I33, and the ends of the pin I iil receive cotter pins MI (Fig. 1) to retain the cylinder I38 in position to always move bodily with the kerf cutting unit. The parts of the telescopic guiding mechanisms are close fitting as they are designed to resist all the feeding strains.

Surrounding each shaft I38 is a pair of concentric cylinders I42 and I43 each movable upwardly and downwardly relatively to the main frame. The cylinder Hi3 fits in the cylinder I19 to slide vertically therein, and the cylinder I42 fits in the cylinder I43 to slide vertically therein after the latter has reached the limit of its upward movement. Adjacent the bottoms of the cylinders I42, I43 and I I9 cylindrical recesses provide annular shoulders for engagement by the circular collars or flanges 544, I 45 and I56 one after another. It will thus be seen that telescopic guiding devices are provided on opposite sides of the main frame and between the latter and opposite sides of the kerf cutting unit. These guiding devices are entirely separate from the screwthreaded lifting device and also entirely separate from the tubular shaft 69. These tubular guiding devices are located at the extreme front corners of the main frame and on opposite sides of the kerf cutting unit so that irrespective of the direction of feeding movement transversely of the kerf cutter, the guiding devices will be in position to resist the feeding strains. During kerf cutting operations the neck I23 fits loosely in the parts to which connected as shown in Fig. 8, and likewise the screw I22 fits loosely in the nut I 3|; consequently the telescopic guiding devices will resist all the feeding strains during feeding movements. While the guiding devices are entirely separate and independent of the lifting mechanism, as shown in Fig. 4, such guiding devices are in the most efiicient position to prevent feeding strains from being imparted to either the lifting screw mechanism or the tubular drive shaft 69, and consequently while the cutter bar is rigidly connected to the main frame by means of the two telescopic guiding devices, the vertical tubular drive shaft 69 may be most efiiciently rotated without tendency toward binding even when the kerf cutting unit is in its most elevated position. Likewise, the lifting mechanism does not tend to bind and may be operated at intervals by increments during feed.

When the kerf cutting unit 2I is elevated, the cylinder I 38 of each of the guiding devices will slide upwardly with respect to the cylinder I 22 until its lower flange I44 engages the shoulder of the cylinder I42. Further upward movement of the kerf cutting unit 2I would cause the cylinder I42 to be lifted with the cylinder I38 until the lower flange I45 engages the shoulder of the cylinder I43, whereupon the latter will be lifted. The limit of the upward sliding movement will be reached when the circular flange I46 of the cylinder I43 engages the annular shoulder of the cylinder II9, the latter being fixed to the main frame.

The mechanism for controlling the rotation of the vertical tubular shaft I24 of the kerf cutting elevating mechanism, is shown in Figs. 3 and 11. Extending upwardly into the splined tubular drive shaft 69 is a vertical shaft I41, the upper end of which is feathered to the internal splines of the tubular drive shaft 69 to permit relative longitudinal movement therebetween but to transfer the rotary movement of the tubular drive shaft 69- to the shaft I41 through the keys I48. Between the shaft I41 and the drive chain I31 I provide a friction clutch I49 comprising a. clutch 'disk I59 having a hub II keyed to the lower end of the shaft I41. The lower end of the shaft I41 is provided with a hardened bearing pin I53 co-operating with a hardened bearing plate I54 set into a recess at the center of a lubricating cup I54 on top of the bottom plate 25.

A shiftable clutch element I55 is provided with a shipper in the form of a split ring I56 having trunnions I51, I51 which are journaled in the arms I 58, I58 pivoted to a shaft I59 mounted upon bosses I66, I60 carried by the bottom plate 25, as shown in Fig. 11. The arms I58, I58 are rigidly attached to a bifurcated split bracket I6I. A trunnion nut I62 co-operates with the bracket I6I and with the vertical threaded shaft I63, as shown in Figs. 6 and 11. By rotating the shaft I63, the arms I58, I58 will be rotated about the axis of the shaft I59 to control the application or release of the clutch I49.

Rigidly attached to the hub of the clutch element I55 is the sprocket I64 which receives the drive chain I31. The sprocket I64 is journaled on the bearing I65 carried by the lower tubular extension I66 rigidly attached to the bottom plate I91 of the top portion of the housing or gearing section 23, as shown in Fig. 3.

By referring to Fig. 6, it Will be seen that the vertical threaded shaft I63 is mounted between the bottom plate 25 and the removable top plate III in position to be rotated by the hand wheel I66 which is keyed to the upper end of the shaft I63 and located outside of the main frame. Hardened bearing pin and plate means I61 is provided for the lower end of the shaft I63.

As shown in Fig. 1, the hand wheel I66 is located in close proximity to the motor control box 29. While the clutch controlled driving mechanism for the kerf cutter elevating apparatus is entirely enclosed within the main frame, the clutch I49 may be operated from without the main frame by rotating the wheel I66 in one direction or the other. The clutch I49 may thus be applied or released but the direction of elevation of the kerf cutting unit will depend upon the direction of rotation of the electric motor 26 which may easily be reversed at the motor control box 29. V

The mechanism for driving the splined tubular shaft 69 from the armature shaft 21 is shown in Fig. 3. The armature shaft 21 extends through an opening I68 in the rear end wall I99 of the gear section 23. The shaft 21 carries a beveled pinion I69 which is keyed to the shaft 21 and is removably held in place by a nut I19 on a screwthreaded extension I 1| at the inner end of the shaft 21.

In mesh with beveled pinion I69 and mounted for free rotation on the axis of the vertical splined tubular drive shaft 69, is a large dishshaped bevel gear I12 provided with a hub portion I13 and a disk portion I13. Secured to the hub portion I13, preferably by welding, is a sleeve or cylinder I14 splined to the outer side of the vertical tubular drive shaft 69.

The hub portion I13 of the dish-shaped bevel gear I12 is journaled to the bearing I15 carried by a downwardly extending cylindrical support I16 formed integral with the removable top plate III, as shown in Fig. 3. The splined sleeve portion I14 at the center of the dish-shaped bevel gear I12 is splined to the vertical drive shaft 69 so as to impart rotation thereto when the motor shaft 21 is rotated. The splined connection between the bevel gear I12 and the vertical tubular drive shaft 69 permits the latter to have free vertical axial movement when the kerf cutting unit is adjusted in elevation. That is to say, provision is made for driving the cutter chain 58 from the motor shaft 21 regardless of the elevated position of adjustment of the kerf cutting unit 2|.

A removable grease seal I11 may be provided at the top of the splined sleeve portion I14 to cooperate with the tubular drive shaft 69. Such grease seal is located on the gear section 23 at the place where the tubular shaft 69 emerges, as shown in Fig. 2.

It will thus be seen that motor operated mech anism is connected through the vertical tubular drive shaft 69 not only to the elevating mechanism but also to the kerf cutting unit. The chain cutter should always be driven in the same direction with any given setting of the cutter bits 59, but when the clutch H is. released and the clutch I49 applied, the electric motor 26 may safely be operated in reverse directions in accordance with the direction of elevation of the kerf cutting unit desired.

In order to assure proper intermeshing of the bevel gear I12 with the pinion I69, I provide a pair of hold-down rollers I18, I18 as shown in Fig. 4. These rollers I18 engage the upper beveled surface of the gear I12 where its circumference is at the maximum. As shown in Figs. 12 and 13, each of the rollers I18 is supported by a stub shaft I19 carried by downwardly extending brackets I89 rigidly secured to the bottom of the removable top plate III. The brackets I89 are each split as shown in Fig. 13 and provided with a clamping screw IBI to hold the stub shaft I19 in any adjusted position to which it may be adjusted by wrench-receiving sockets I82. The rollers I18 may be mounted upon the stub shafts. I19 by means of ball bearings I83.

For the sake of compactness of operating parts and to maintain the overall length of the main frame at a minimum, I mount the feeding rope drum I84 within the top portion of the housing of the gear section 23, in a position where such rope drum will be concentric with the vertical axis of the tubular drive shaft 69. I also compactly locate planetary gear controlling mechanism within the hollowed out portion of the dish-shaped bevel gear I12 and even within the hollowed out portion of the feed drum I84 itself. The planetary gear control mechanism may be operated to effect rotation of the feed rope drum I84 either at a relatively slow feeding speed during kerf cutting operations, or at a relatively high handling speed when the mining machine is to be moved-quickly from one place to another.

As shown in Figs. 3'an'd 4, an eccentric I is keyed to the hub I13 of the bevel gear I'I2. Surrounding the eccentric I85 is a bearing I86 on which is journaled a gear I87. The gear I8? is connected by welding, as shown in Fig. 3, to a horizontal plate I88 which'has a bifurcated extension I89 provided with a slot I98 slidable with respect to a roller I9! carried by a vertical stub shaft I92 secured to a stationary bracket I93 by a pin I9 5. The bracket I93 is secured by means of the machine screws I95 to the horizontal plate II8, as shown in Fig. 4. Lubricant may be introduced by way of the conduit I96 to the bearing surfaces between the roller NH and the stub shaft I92, as shown in Fig. 3.

Cooperating with the gear I8? is a second gear I9: which is mounted upon a hub I98 by being welded thereto, as shown in Fig. 3. The hub- I98 is spaced from the hub I13 of the dish-shaped bevel gear I72, by journal bearing I99. To the bottom of the hub I98 is welded, as shown in Fig. 3, a sun gear2fl0 concentric with the vertical axis of the tubular shaft 69. The sun gear 200 forms part of a planetary type of transmission as best seen by referring to Fig. 10.

Reverting to the power transmitting connections between the motor shaft 2'3 and the gear I97, it should be noted that rotation of the eccentric I85 will cause the gear I8"! to walk around the gear I9! while meshing with the teeth thereof. The gear I8! will be held against rotation because of its being rigidly secured to the plate I38 by being welded thereto, as shown in Fig. 3. The plate I88 is held against rotation by the roller ISI on the stationary vertical shaft I92 which is rigidly secured to the plate I I8. But by reason of the slot I 98 co operating with the roller IQI, the plate I88 will be free to oscillate as re quired by the eccentric I85.

The gear IB'I has fewer teeth than the gear I91. In the accompanying drawings, the gear I8! has fifty-five teeth and the gear IEI'I has fiftyeight teeth. Consequently for each rotationof the dish-shaped bevel gear In there will be a complete rotation of the eccentric I85. If this is in a clockwise direction, the gear I91 willbe rotated a slight amount correspondingly. -For instance, for each rotation of the eccentric I85, gear I91 will move 1 of arotation, or of a rotation. Consequently the speed reduction between the gear I'I2 and the gear I91 will be It will of course be obvious that this reduced speed will be transmitted from the gear I91 directly to the sun gear 28f! through the hub I98. The sun gear 200, as shown in Fig. 10,-meshes with the four planetary gears 2M which are mounted upon four upstanding shafts 202 carried by a spider 203 mounted upon a cylindrical support 2M which is journaled upon the hub 295 of the feed drum I84, asshown in Fig, 3. The hub 265 is journaled on the bearing 266 carried by the cylindrical support 201, and the latter in turn welded to the bottom plate I07, as shown in Fig. 3.

Each of the vertical shafts 202 is provided with an upper bearing portion 208 which extends into a journal bearing for a roller 289. An integral annular flange 2H] is provided on the shaft 262- at its upper end portion in position to support the roller 269. The rollers 209 are adapted to roll upon the outer surface of the hub I 98; A springpressed wiping member 2 is provided adjacent th'e upper'e'nd of "said shaft 202 to provide lubri- .Cation for the roller 209. Below the annular flanges 2I0, the vertical shafts 202 each extends through the hub of the brake drum 2I2 which is formed'integral with the spider 263. This can readily be seen by referring to Fig. 10 which is a sectional plan view taken on the line I6, III of Fig. 3. A brake band 2I3 provided with a brake lining 2M is associated with the drum 2I2.

The planetary gears 2M are rotatably mounted with respect to the vertical shafts 232 by double antifriction roller bearings 2I5. Each of said planetary gears 2M is provided with a hub ilIt, to the upper portion of which the gear 2M is integrally attached, and to the bottom portion of which is attached a planetary gear ZI'I. In other words, as shown in Fig. 3, the hub 2H5 carries both the planetary gear ZiiI and the planetary gear 2H, and therefore both gears 2B! and 2H always rotate together.

Planetary gears 2 I1 mesh with a ring gear 2I8 rigidly secured to the interior of the operating drum I84. It will thus be seen that the planetary gear 293i meshes with the sun gear 280, that the planetary gear ZIII is connected to the planetary gear 2 I I, and the latter meshes with the gear 2 I8 but is secured to the rope drum I8 3.

Not only do the planetary gears 2M mesh with the sun gear 298, but also with the ring gear 2I9 which is integral with the brake drum 2%. The brake drum 220 is mounted upon a journal bearing 22I carried on the interior peripheral portion of the rope drum I84. Associated with the brake drum 229 is a brake band 223 provided with a lining 224.

By referring particularly to Fig. 10 of the drawings, it will be seen that the planetary gears ZElI have fewer teeth than the planetary gears 2, the number of the teeth on each gear 2M being fourteen, and the number of teeth on each gear ZI'I being sixteen.

As will be described more fully hereinafter, the brake bands 2I3 and 223 are so interlocked that it will be impossible to clamp both of them at the same time, and a single operating mechanism is provided whereby when one of said brake mechanisms is applied, the other is released, and vice versa. The brake bands may also be so adjusted that neither will be applied, under which condition power will not be transmitted to the rope drum I 84 from the motor shaft 27 but will be 'free'to be rotated by the operator grasping the-feed rope and pulling it out from the main frame of the machine and thereby freely rotating the rope drum.

By referring to Fig. 3 of the drawings, it will be seen that if the brake band 2 I3 is applied to the brake drum 2 I2 to hold the same stationary, the rotation of the sun gear 290 will be transmitted to the planetary gears 2I1I and 2I'I. When the brake drum 2I2 is held stationary, the axes of the vertical shafts 282 will also be held stationary because they are mounted on the brake 2I2 to revolve around the vertical axis of the tubular shaft 69 only when the brake drum H2 is free to rotate.

At the time that the brake 2 I3 is applied to the drum 2 I2, the brake 223 is released and therefore the brake drum 220 is free to rotate. Rotation of the planetary gears am about the vertical stationary axes of the shafts 202, will be trans mitted to the brake drum 22!! but this will have no effect because the brake drum 226 at this time is free to rotate;

The rotation of the planetary gears ZII, however, will effect rotation of the annular gear2l8 which is secured as by welding to the inner side of the large rope drum I84. It will thus be seen that when the brake 223 is released from the brake drum 223 but the brake 2I3 is applied to the brake drum 2I2, rotation of the armature shaft 21 will rotate the sun gear 20!], and the planetary gears 2I'I will be rotated on vertical stationary axes 202 to effect rotation of the rope drum I84 on the vertical axis of the tubular drive shaft 69.

The planetary gears 2", as shown in Fig. 10, are somewhat larger than the planetary gears 20!, so as to secure a predetermined ratio of the number of teeth on the planetary gears 2ilI and 2". In Fig. 10 this ratio is illustrated as being 14 to 16. It will thus be seen that when the sun gear effects a complete rotation of each of the planetary gears 2M, 14 teeth will be engaged, but 16 teeth of each of the planetary gears 2I'I will become effective in their meshing with the internal annular gear ZIB which is secured to the inner wall of the rope drum I82. The transmission of power to the rope drum from the sun gear 230 will therefore be at a relatively fast speed when the brake 2I3 is applied to the brake drum 2I2 While the brake drum 223 is released. This relatively fast speed of rotation of the drum I84 is useful in handlingthe mining machine when it is to be moved from one place in the mine to another while the cutting mechanism is not cutting a kerf.

When the brake 2I3 is released and the brake 223 applied to the brake drum 223, a very slow feeding speed of rotation of the drum I34 will be secured. This feeding speed is used when the kerf cutter is cutting a kerf while the machine is being slid over the mine bottom by the feed rope I 32 controlled by the retarding or guide rope 34.

When the brake 2 I3 is released and the brake 223 applied to the brake drum 220, the latter together with its inner annular gear 2W will be held stationary. Since the brake drum 292 is free to rotate, the vertical shafts 232 are free.

to revolve about the vertical axis of the tubular drive shaft 69. Rotation of the sun gear 20!! will cause rotation of the planetary gears 2M on the vertical bearings 202. Since the brake'drurn 220 is held stationary together with its gear 219, the planetary gears 20I will walk around the stationary ring gear 2I9.

In making a complete rotation, the planetary gears 2!, each of which has 14 teeth, will have caused 16 teeth of each of the planetary gears 2I'I to mesh with the ring gear 2I8, because whenever any planetary gear 2! makes a complete rotation, the planetary gear 2I1 attached thereto will also make a complete rotation. In other words, while the planetary gear 2m walks around the stationary gear 2 I 9, the-distancerepresented by 14 teeth, the planetary gear 2II will attempt to walk around the gear M9, the distance represented by 16 teeth. The diiferenceof two teeth represents the distance which the rope drum will be rotated during each rotation of the planetary gear 2I'I. That is to say, due to the difference in the number of teeth between the planetary gears 2M and 2I'I, it will be necessary for the ring gear 2I8 to rotate in response to the sun gear walking the planetary gear 2EII around the ring gear 2 I9 while the latter is being held stationary by the brake 223 being applied to the brake drum 220.

The planetary gear mechanism shown in Fig. 3,

controlled by the brakes applied to the brake drums 2 I 2 and 220, enables the power to be trans.- mitted to the rope drum to rotate the same either at a fast handling speed or at a greatly reduced feeding speed. When both brake drums 2I2 and 220 are released by releasing the brakes 2I3 and 223, the rope drum I 84 will be free to rotate so that the rope I02 on the rope drum I34 may be pulled out manually from the machine for the purpose of connecting it to an anchorage in the mine distant from the machine.

When power is transmitted to the rope drum I84 to rotate the same, a-wide range of speeds. of rotation of this rope drum may be obtained by partially applying either of the brakes 2I3 or 223 to the brake drums 2I2 and 223, so that slipping may occur between the brake drums and the brake linings 2M and 224. It should be understood, however, that when one brake is applied the other is released.

The mechanism for operating the brake bands 2I3 and 223 so that both may be released at the same time or either applied while the other is released, is shown particularly in Figs. 4, 6 and '7. The construction for applying one of the brake bands is substantially the reversal of the construction for applying the other brake band. Upon the horizontal supporting plate II8 is secured, by means. of machine screws H8, H8, a casting 326 having a pair of integral brackets 225 and 226. The left-hand bracket 226 as viewed in Fig. 6 is provided with an adjustable stop screw 221 which co-operates with a spring-pressed lug 228 carried by one end of the brake band 2 I3, the other end of which carries a lug 229 adapted to be received by spaced abutment means 230 carried by a slide plate 23I. The lug 228 is held against the stop screw 221 by a spring 232 co-operating with the stationary abutment 233 carried by the stationary casting 326. It can readily be seen by referring to Figs. 6 and '7, that if the slide plate 23I is moved to the left, the brake band 2I3 will be applied to the brake drum 2I2, and if the slide 23I is moved to the right, as viewed in Fig. '7, the brake band 2I3 will be released. In other words, when the slide 23! is moved toward the left, the abutment means 239 will engage the lug 229 to apply the brake band 2I3 to the brake drum 2 I2, while the lug 228 is held by the spring 232 against the adjustable screw stop 22'! carried by the stationary bracket 226 which is integral with the casting 326 and the latter secured rigidly to the horizontal supporting plate II8.

It should be noted that Fig. 6 is a section taken on the line 6-6 of Fig. 4, looking in the direction of the arrows. Extending into the lower portion of the bracket 225 is a horizontal adjustable stop screw 234 which corresponds in function to the stop screw 22'! but is associated with the mechanism for applying the brake band 223, whereas the stop screw 221 is associated with the mechanism for applying the brake band 2I3. As shown in dotted lines in Fig. 6, a lug 229 extends from one end of the brake band 223 into a recess between abutment means similar to that designated 230 in Fig. '7. Also as shown in dotted lines in Fig. 6, a spring 232 is associated with a lug 228 and the latter held by the spring 232' against the stop screw 234.

By reason of the reverse arrangement of the mechanism for operating the brake band 223, the slide plate 23I is moved to the left as viewed in Fig. '7 to apply the brake band 2 I3 to the brake drum 2l2, but this slide is moved toward the right'as viewed in Figs-6 and '7 to effect the application of the brake band 223 and at the same time release the brake band 2I3. It will thus be seen that whenever the slide 23I is moved in one direction to apply one brake band, the other will be released, and the interlocking is such that both brake bands can not be applied at the same time.

As shown in Fig. 6, a horizontal plate 3IB secured to the walls H0, I I is provided to serve as a slide bearing for the slide plate 23L By means of appropriate bracket plates 235, 235, as shown in Fig. '7, and by overhanging guide bracket 335 integral with the casting 323, the slide plate 23I will be provided with suitable guiding devices to maintain the slide plate 23I in a rectilinear, oscillatory path of travel. Oscillatory movement may be imparted to the slide 23I to apply either the brake band 2I3 or the brake band 223, by means of a pitman 236 pivotally attached to the slide 23I by means of a keyed pin 23?. As shown in Fig. 4, the pitman 236 is pivoted eccentrically at 238 to a rotary cylinder 239 mounted in appropriate bushings in a cup 243 rigidly secured to an extension of the casting 326, as shown in Fig. 4. The upper end of the cup 220 may be provided with lubricating packing 24! (Fig. 6).

Secured to the cylinder 239 intermediate its ends is a worm gear 242 which meshes with a worm 243 (Fig. 4) carried by a shaft 244 extending through the adjacent vertical frame plate H3. The shaft 244 is journaled in the roller bearings 243, 243 carried by the removable tubular support 245. Keyed to the shaft 244 outside of the frame of the machine is an operating handle 241 located adjacent to the horizontal wheel I33 and also adjacent the motor control box 29, as shown in Fig. 1.

As may be seen by referring to Fig. 1, a single operator standing on the leading side of the machine may have within his reach the wheel I63 for controlling the elevation of the kerf cutting unit, the reversing switch lever 3! for controlling the direction of rotation of the motor 26, the control lever 32 for effecting the starting and stopping of the electric motor 23, and the wheel 24? for controlling the speed of movement of the machine when slid over the mine floor by rotation of the drum I84 exerting a pull on the rope I02 while its free end is anchored to the machine and an intermediate portion of the rope I32 reeved through a pulley connected to an anchorage in the mine, distant from the machine. When the hand wheel 24'! is moved to a neutral position, both of the brake bands 2I3 and 223 will be released and no power will be transmitted from the motor 23 to the rope drum I84, but the latter will be free to be rotated by the manual pulling out of the rope I02. Upon rotatingthe hand wheel 23! in one direction, the rope drum will be rotated at a fast or handling speed when the machine is to be moved about the mine from place to place. During handling operations the rope I32 becomes. a haulage rope and may be extended around the vertical rollers 38 and 39 and thence reeved through the pulley 33 so that when the free end of the rope I32 is connected to an anchorage in the mine and the rope dru-m I83 operated by the motor 23, the whole machine may be slid over the mine bottom rearwardly and longitudinally.

It should also be understood that the rope I02 may be connected to the rope drum I84 and mounted thereon in either direction, depending upon the direction of feeding movement of the mining machine. When the feed is opposite to that shown in Fig. 1, the cutter bits 59 should be reversed and the guide rope 34 extended in an opposite direction to an anchorage in the mine.

Not only have I completely enclosed all of the operating parts shown in Fig. 3, within the housing of the main frame, except for the openings 248 and 249 for the rope I02, but I have also provided planetary gear mechanism to secure great reduction in speed and variation in speed of transmission to the rope drum I84 although employing a rope drum of relatively large diameter, which has the advantage of prolonging the life of the feed rope I02 by reducing to a minimum the necessary bending thereof. The pull on the guide rope 34 is relatively small but the pull on the feed rope I02 during coal cutting operations is relatively very large and consequently it is desirable to use a very strong feed rope I02 and prolong its life by reducing to a minimum the necessary bending thereof.

The openings 248 and 249 shown'in Fig. 2 may be provided on both sides of the machine, and likewise a guide pulley 25I may be provided on that side of the machine opposite to the guide pulley 250.

When the cutter bits 59 are arranged as shown in Fig. 1, and the feed and guide ropes I02 and 34 are arranged as shown in this view, the direction of feeding movement will be in accordance with the direction of thearrow 252, with the rope drum I84 operating in a clockwise direction as viewed in plan. While the brake 223 is applied and the brake 2I3 released, the sun gear 200 will transmit to the rope drum I84 a slow feeding speed.

During the feed of the kerf cutting mechanism in the direction of the arrow 252 of Fig. 1, the retarding rope drum mechanism 35 Will pay out the rope 34 as permitted by the slipping of the partially applied clutch or brake elements 41, 49 as controlled by the wheel 52. To reduce the overall length of the main body of the machine when fed between an elongated conveyor and the coal face, the direction pulley 33 may be detached from the rear side of the motor section 22 by removal of the cotter pin 253 shown in Fig. 5.

When the feed rope I02 is extended from the machine and its intermediate portion reeved through a pulley on a snatch block connected to a roof jack at a point in the mine distant from the machine, it should be understood that the elevation of such snatch block may be adjusted vertically along the roof jack so as to cooperate with the anchorages of the free end of the rope to the machine, in securing the desired balanced pulls on the lower and upper portions of the mining machine structure considered as a Whole.

When sumping operations are to be performed in the working face adjacent to the rib, the feed rope I02 is disconnected from its anchorage I00 shown in Fig. 1, and the rope I02 is reeved around the rollers 38, 39, pulley 33, roller 33, and pulley 25I, and the free end of the rope I02 connected to an anchorage between the cutter bar and the rib. The retarding rope 34 is then preferably extended from that side of the machine opposite to that shown in Fig. 1 and so connected to such anchorage in the mine near the rear end of the machine, as to enable the controlling mechanism shown in Fig. 5 to cause such retardation of the rope drum 44 as to co-operate with the sumping of the kerf cutter into the coal face, first at an angle to the rib and then parallel thereto when the sumping cut is completed. After such sumping cut has been made, the connections of the ropes I02 and 34 may be restored to the position shown in Fig. l, whereupon the feed of the kerf cutter may continue from the sumping out, in the direction of the arrow 252. A lateral extension 338 from the lower bracket 339 (Fig. 1) may be used to prevent the feed rope I02 from running off the roller 36.

It should be particularly noted that the dishshaped support M3 for the large bevel gear I12 not only provides ample space for the planetary gear brake mechanism beneath and within the same, but also eliminates additional gearing meshing with the bevel pinion [69 while the shaft 21 is maintained in a relatively low position so that the bottom of the motor section 22 may make direct sliding contact with the mine bottom while rigidly connected to the gear section 23, as shown in Fig. 2.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and I therefore wish not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of my invention, what I desire to secure by Letters Patent of the United States is:

1. In a mining machine, the combination with a frame, of an operating drum mounted thereon for rotation, a motor, means for driving said operating drum from said motor comprising a gear mounted against rotation and adapted to walk around another gear, a planetary mechanism including two brake drums, means for restricting rotation of said brake drums alternately, and means constructed and arranged to rotate said operating drum at a relatively fast speed when one drum is restricted, and at a relatively slow speed when the other drum is restricted.

2. In a mining machine, the combination with a frame, of a motor carried thereby, a feed drum mounted for rotation on a vertical axis intermediate the frame side and ends, drive means for said drum including a large dished drive gear intermeshing a pinion driven from said motor, said gear being positioned above said drum with the open side facing downwardly, and planetary gearing mechanism connecting said drum and drive gear and positioned above said drum and at least partially within said gear, said drum having a smaller diameter than that of said large gear and being positioned with its topmost portion above and axially inwardly of the bottom of said pinion.

3. In a mining machine, the combination with a frame, of a drum mounted thereon, said drum being dish shaped, a dish shaped drive gear of larger diameter than said drum, a motor and an intermeshing pinion for driving said gear, and speed reduction mechanism connecting said gear and drum, said gear and drum cooperating to form a housing for said speed reduction mechanism due to their complementary dish shapes, said drum having its topmost portion above the bottommost portion of said pinion.

4. In a mining machine, the combination with a frame, of a dish shaped gear mounted for rotation on a vertical axis, a drum mounted on said axis and below said gear, an eccentric driven by said gear and housed within it, a toothed gear driven in an eccentric motion by said eccentric, means for holding said toothed gear against rotation while allowing said eccentric motion thereof, an internally toothed gear meshing with said toothed gear and having a greater pitch diameter and more teeth, means for driving said dished gear to cause said internally toothed gear to rotate at a reduced speed, and means connecting said internally toothed gear to said drum.

5. In a mining machine, the combination with a frame, of a drum mounted for rotation on said frame, said drum being dished between its hub and face, and means for driving said drum including a planetary gear mechanism at least part of which is housed in said dished drum and positioned between the hub and face thereof.

6. A compact speed reducing mechanism com.- prising a rotating gear, a planetary gear mechanism including a sun gear connected with said rotating gear, an eccentric, said rotating gear, sun gear and eccentric being all mounted to rotate on a common axis, gear holding means, and another gear connected to be driven in an eccentric movement by said eccentric whilebeing held against rotation by said gear holding means, said rotating gear and other gear having meshing teeth, one of said two last mentioned gears having internal teeth and the other external teeth.

7. In a device of the class described, the combination with a drum, of a means for driving said drum including a large gear rotatable on an axis concentric therewith, speed reducing mechanism interconnecting said gear and said drum including a planetary gear mechanism having a sun gear rotatable on said axis, and drive means for said sun gear including a pair of intermeshing gears one of which is internally toothed and the other externally toothed, means holding one of said pair of gears against rotation, the other driving said sun gear, and an eccentric mounted for rotation on said axis and imparting an eccentric motion to said one gear which is held against rotation.

8. In a device of the class described, the combination with a drum, of a means for driving said drum including a pair of gears one of which is internally toothed, the other of which is inside said one gear, has fewer teeth, and is externally toothed and meshing therewith, means including an eccentric for causing one of said gears to walk around the other while being held against rotation thereby causing said other gear to rotate, and a two speed planetary gear mechanism interconnecting said rotating gear and said drum.

9. Rope drum. feeding mechanism for a mining machine comprising a supporting frame, a rope drum, an internal gear carried by said rope drum, a brake drum having an internal gear, a plurality of pairs of planetary gears meshing with said internal gears, an additional brake drum, mechanism for supporting said planetary gears on said additional brake drum for bodily rotation therewith or for rotation on their own axes relatively to said additional brake drum, brake mechanism associated with said brake drums, interlocking mechanism for operating the brake mechanism associated with either brake drum While the brake mechanism associated with the other brake drum is held released, and motor operated mechanism connected to said planetary gears to drive the same to effect either relatively fast rotation of said rope drum or relatively slow rotation thereof dependent upon the application of the aforesaid brake mechanisms.

10. In a device, of the class described, the combination with a drum, of means for driving said drum including a rotating gear, a planetary gear mechanism including a sun gear connected with said rotating gear, an eccentric, said drum, rotating gear, sun gear and eccentric being all mounted to rotate on a common axis, gear holding means, and another gear connected to be driven in an, eccentric movement by said eccentric while being held against rotation by said holding means, said rotating gear and other gear having meshing teeth, one of said last mentioned gears having internal teeth and the other external teeth.

11. In a device of the class described, the combination with a drum, of means for driving said drum including a planetary gear mechanism having a sun gear rotatable on the axis of said drum, and drive means for said sun gear including a pair of intermeshing gears one of which is internally toothed and the other externally toothed, means holding one of said pair of gears against rotation, the other driving said sun, and an eccentric mounted for rotation on said axis and imparting an eccentric motion to said one gear which is held against rotation.

12. In a device of the class described, the combination with a drum, of means for driving said drum including a planetary gear mechanism having a sun gear rotatable on the axis of said drum, and drive means for said sun gear including a pair of intermeshing gears one of which is internally toothed and the other externally toothed, means holding one of said pair of gears against rotation, the other driving said sun, and an eccentric mounted for rotation and imparting an eccentric motion to said one gear which is held against rotation.

13. In a mining machine, the combination with a frame, of an inverted dish shaped gear mounted on said frame for rotation, a pinion meshing with said gear for driving it, a motor connected to drive said pinion, an upright dish shaped drum mounted to rotate coaxially with said drum, and speed reduction mechanism comprisingplanetary gearing having a sun gear mounted for rotation on the axis of said drum and dish shaped gear connecting said drum and gear, said drum and gear having their nearest peripheral points close together to provide a housing for said speed reduction mechanism, said peripheral spacing being less than the minimum diameter of said pinion.

14. In a mining machine, the combination with a frame, of an inverted dish shaped gear mounted on said frame for rotation, a pinion meshing with said gear for driving it, a motor connected to drive said pinion, an upright dish shaped drum mounted to rotate coaxially with said drum, and speed reduction mechanism connecting said drum and gear, said drum and gear having their nearest peripheral points close together toprovide a housing for said speed reduction mechanism, said peripheral spacing being less than the minimum diameter of said pinion.

15. In a mining machine, the combination with a frame, of a drum journaled to said frame, said planetary gears in the dished portion of the drum and driving mechanism connected between said planetary gears and the hub portion of the gear, the construction and arrangement being such that the power-transmission mechanism. surrounds the closely adjacent hubportions of the gear and drum and is confined within the space afforded by the dishing of the drum and gear.

'16. In a mining machine, the combination with a casing, of a bearing within the same depending from the top thereof, a gear journaled on said bearing closely adjacent the underside of the top of said casing, a drum mounted within said casing to rotate on an upright axis concentric with the axis of rotation of said gear, and power-transmission mechanism between the hub portion of said gear and the internal peripheral portion of said drum, said drum being dished to house a portion of such power-transmission mechanism.

17. In a mining machine, the combination with a casing, of a bearing depending from the top thereof within the casing, a driving gear journaled on said bearing adjacent to the underside of the top of said casing, a driven element connected to the hub portion of the gear and extending upwardly within said bearing, a drum mounted within said casing to rotate on an upright axis concentric with the axis of rotation of said gear, and power-transmission mechanism between the hub portion of said gear and said drum.

18. In a mining machine, the combination with a casing, of a cylindrical bearing depending from the top of said casing to project downwardly intothe same, a gear journaled to said bearing closely adjacent the underside of the top of said casing, a driven element connected to the hub portion of said gear and extending upwardly into said cylindrical bearing, a drum, a cylindrical bearing projecting upwardly from the bottom of the casing with the drum journaled on such upwardly projecting bearing for rotation concentrically with the rotation of the gear with the lower side of the drum closely adjacent the bottom of the casing and with the hub portion of the drum closely adjacent the lower end of said driven element, and power-transmission mechanism between the said gear and said drum, said drum being dished on its upper side to receive a portion of such power-transmission mechanism the remainder of which surrounds the hub portion of the gear.

19. In a mining machine, the combination with a gear casing limited in height and adapted to rest on and slide over a mine bottom, of a bearing depending from the top of said casing, a gear journaled on said bearing adjacent thelower side of the top of said casing, a drum, a journal bearing for mounting said drum at the lower interior of said casing concentric with said .gear, and power-transmission mechanism between the hub portion of said gear and the inner peripheral portion of said drum, said drum being dished at its upper side for receiving a portion of said power-transmission mechanism to enable the latter and said gear and said drum to occupy the limited space within the casing of limited height.

20. In a mining machine, the combination with a casing, of a depending journal bearing within the upper interior of said casing, an upwardly extending journal bearing within the casing, a gear journaled on the depending bearing, a drum journaled on the upwardly extending bearing concentric with said gear, two annular gears within the periphery of said drum in the dish-shaped upper side, planetary gears within such dishshaped upper side and associated with said annular gears one of which is secured to said drum to rotate therewith and the other of which is journaled to the drum to rotate relatively thereto, driving gearing connected between said firstnamed gear and said planetary gears, brake mechanism connected to said planetary gears to hold the same against revolution around said upwardly extending bearing and thereby effect relatively fast rotation of said drum when said driving gearing is operated, and brake mechanism associated with said journaled annular gear to hold the same stationary when the first-named brake mechanism is released and thereby effect relatively slow rotation of the drum, the construction and arrangement being such that when both brake mechanisms are released the drum will be freed for rotation by manual pull on a rope connected to and Wound on the drum.

21. In a mining machine, the combination with a supporting frame, of a drum carried thereby for rotation relatively thereto and adapted to have a feed rope connected thereto and wound on the periphery thereof, said drum being annularly open on one side Within such periphery, planetary gearing connected to the inner annular periphery of said drum and located in the opening in one side of the drum within the inner and outer peripheries of said drum, and powertransmission mechanism connected tosaid planetary gearing at one side of said opening to have a circular driving path of travel concentric with said drum and spaced from its axis of rotation.

LEWIS E. MITCHELL. 

